Author: gordon
Date: Mon Dec 24 21:10:07 2007
New Revision: 45351
URL: http://llvm.org/viewvc/llvm-project?rev=45351&view=rev
Log:
GC poses hazards to the inliner. Consider:
define void @f() {
...
call i32 @g()
...
}
define void @g() {
...
}
The hazards are:
- @f and @g have GC, but they differ GC. Inlining is invalid. This
may never occur.
- @f has no GC, but @g does. g's GC must be propagated to @f.
The other scenarios are safe:
- @f and @g have the same GC.
- @f and @g have no GC.
- @g has no GC.
This patch adds inliner checks for the former two scenarios.
Added:
llvm/trunk/test/CodeGen/Generic/GC/inline.ll
llvm/trunk/test/CodeGen/Generic/GC/inline2.ll
Modified:
llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp
Modified: llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp?rev=45351&r1=45350&r2=45351&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp Mon Dec 24 21:10:07 2007
@@ -201,6 +201,19 @@
BasicBlock *OrigBB = TheCall->getParent();
Function *Caller = OrigBB->getParent();
+
+ // GC poses two hazards to inlining, which only occur when the callee has GC:
+ // 1. If the caller has no GC, then the callee's GC must be propagated to
the
+ // caller.
+ // 2. If the caller has a differing GC, it is invalid to inline.
+ if (CalledFunc->hasCollector()) {
+ if (!Caller->hasCollector())
+ Caller->setCollector(CalledFunc->getCollector());
+ else if (CalledFunc->getCollector() != Caller->getCollector())
+ return false;
+ }
+
+
// Get an iterator to the last basic block in the function, which will have
// the new function inlined after it.
//
Added: llvm/trunk/test/CodeGen/Generic/GC/inline.ll
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Generic/GC/inline.ll?rev=45351&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/Generic/GC/inline.ll (added)
+++ llvm/trunk/test/CodeGen/Generic/GC/inline.ll Mon Dec 24 21:10:07 2007
@@ -0,0 +1,23 @@
+; RUN: llvm-as < %s | opt -inline | llvm-dis | grep example
+
+ %IntArray = type { i32, [0 x i32*] }
+
+declare void @llvm.gcroot(i8**, i8*) nounwind
+
+define i32 @f() {
+ %x = call i32 @g( ) ; <i32> [#uses=1]
+ ret i32 %x
+}
+
+define internal i32 @g() gc "example" {
+ %root = alloca i8* ; <i8**> [#uses=2]
+ call void @llvm.gcroot( i8** %root, i8* null )
+ %obj = call %IntArray* @h( ) ; <%IntArray*> [#uses=2]
+ %obj.2 = bitcast %IntArray* %obj to i8* ; <i8*> [#uses=1]
+ store i8* %obj.2, i8** %root
+ %Length.ptr = getelementptr %IntArray* %obj, i32 0, i32 0
; <i32*> [#uses=1]
+ %Length = load i32* %Length.ptr ; <i32> [#uses=1]
+ ret i32 %Length
+}
+
+declare %IntArray* @h()
Added: llvm/trunk/test/CodeGen/Generic/GC/inline2.ll
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Generic/GC/inline2.ll?rev=45351&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/Generic/GC/inline2.ll (added)
+++ llvm/trunk/test/CodeGen/Generic/GC/inline2.ll Mon Dec 24 21:10:07 2007
@@ -0,0 +1,24 @@
+; RUN: llvm-as < %s | opt -inline | llvm-dis | grep sample
+; RUN: llvm-as < %s | opt -inline | llvm-dis | grep example
+
+ %IntArray = type { i32, [0 x i32*] }
+
+declare void @llvm.gcroot(i8**, i8*) nounwind
+
+define i32 @f() gc "sample" {
+ %x = call i32 @g( ) ; <i32> [#uses=1]
+ ret i32 %x
+}
+
+define internal i32 @g() gc "example" {
+ %root = alloca i8* ; <i8**> [#uses=2]
+ call void @llvm.gcroot( i8** %root, i8* null )
+ %obj = call %IntArray* @h( ) ; <%IntArray*> [#uses=2]
+ %obj.2 = bitcast %IntArray* %obj to i8* ; <i8*> [#uses=1]
+ store i8* %obj.2, i8** %root
+ %Length.ptr = getelementptr %IntArray* %obj, i32 0, i32 0
; <i32*> [#uses=1]
+ %Length = load i32* %Length.ptr ; <i32> [#uses=1]
+ ret i32 %Length
+}
+
+declare %IntArray* @h()
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